xref: /linux/drivers/target/target_core_pscsi.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_pscsi.c
4  *
5  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
6  *
7  * (c) Copyright 2003-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  ******************************************************************************/
12 
13 #include <linux/string.h>
14 #include <linux/parser.h>
15 #include <linux/timer.h>
16 #include <linux/blkdev.h>
17 #include <linux/blk_types.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/genhd.h>
21 #include <linux/cdrom.h>
22 #include <linux/ratelimit.h>
23 #include <linux/module.h>
24 #include <asm/unaligned.h>
25 
26 #include <scsi/scsi_device.h>
27 #include <scsi/scsi_host.h>
28 #include <scsi/scsi_tcq.h>
29 
30 #include <target/target_core_base.h>
31 #include <target/target_core_backend.h>
32 
33 #include "target_core_alua.h"
34 #include "target_core_internal.h"
35 #include "target_core_pscsi.h"
36 
37 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
38 
39 static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
40 {
41 	return container_of(dev, struct pscsi_dev_virt, dev);
42 }
43 
44 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
45 static void pscsi_req_done(struct request *, blk_status_t);
46 
47 /*	pscsi_attach_hba():
48  *
49  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
50  *	from the passed SCSI Host ID.
51  */
52 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
53 {
54 	struct pscsi_hba_virt *phv;
55 
56 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
57 	if (!phv) {
58 		pr_err("Unable to allocate struct pscsi_hba_virt\n");
59 		return -ENOMEM;
60 	}
61 	phv->phv_host_id = host_id;
62 	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
63 
64 	hba->hba_ptr = phv;
65 
66 	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
67 		" Generic Target Core Stack %s\n", hba->hba_id,
68 		PSCSI_VERSION, TARGET_CORE_VERSION);
69 	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
70 	       hba->hba_id);
71 
72 	return 0;
73 }
74 
75 static void pscsi_detach_hba(struct se_hba *hba)
76 {
77 	struct pscsi_hba_virt *phv = hba->hba_ptr;
78 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
79 
80 	if (scsi_host) {
81 		scsi_host_put(scsi_host);
82 
83 		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
84 			" Generic Target Core\n", hba->hba_id,
85 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
86 			"Unknown");
87 	} else
88 		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
89 			" from Generic Target Core\n", hba->hba_id);
90 
91 	kfree(phv);
92 	hba->hba_ptr = NULL;
93 }
94 
95 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
96 {
97 	struct pscsi_hba_virt *phv = hba->hba_ptr;
98 	struct Scsi_Host *sh = phv->phv_lld_host;
99 	/*
100 	 * Release the struct Scsi_Host
101 	 */
102 	if (!mode_flag) {
103 		if (!sh)
104 			return 0;
105 
106 		phv->phv_lld_host = NULL;
107 		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
108 
109 		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
110 			" %s\n", hba->hba_id, (sh->hostt->name) ?
111 			(sh->hostt->name) : "Unknown");
112 
113 		scsi_host_put(sh);
114 		return 0;
115 	}
116 	/*
117 	 * Otherwise, locate struct Scsi_Host from the original passed
118 	 * pSCSI Host ID and enable for phba mode
119 	 */
120 	sh = scsi_host_lookup(phv->phv_host_id);
121 	if (!sh) {
122 		pr_err("pSCSI: Unable to locate SCSI Host for"
123 			" phv_host_id: %d\n", phv->phv_host_id);
124 		return -EINVAL;
125 	}
126 
127 	phv->phv_lld_host = sh;
128 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
129 
130 	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
131 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
132 
133 	return 1;
134 }
135 
136 static void pscsi_tape_read_blocksize(struct se_device *dev,
137 		struct scsi_device *sdev)
138 {
139 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
140 	int ret;
141 
142 	buf = kzalloc(12, GFP_KERNEL);
143 	if (!buf)
144 		goto out_free;
145 
146 	memset(cdb, 0, MAX_COMMAND_SIZE);
147 	cdb[0] = MODE_SENSE;
148 	cdb[4] = 0x0c; /* 12 bytes */
149 
150 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
151 			HZ, 1, NULL);
152 	if (ret)
153 		goto out_free;
154 
155 	/*
156 	 * If MODE_SENSE still returns zero, set the default value to 1024.
157 	 */
158 	sdev->sector_size = get_unaligned_be24(&buf[9]);
159 out_free:
160 	if (!sdev->sector_size)
161 		sdev->sector_size = 1024;
162 
163 	kfree(buf);
164 }
165 
166 static void
167 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
168 {
169 	if (sdev->inquiry_len < INQUIRY_LEN)
170 		return;
171 	/*
172 	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
173 	 */
174 	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
175 	snprintf(wwn->vendor, sizeof(wwn->vendor),
176 		 "%." __stringify(INQUIRY_VENDOR_LEN) "s", sdev->vendor);
177 	BUILD_BUG_ON(sizeof(wwn->model) != INQUIRY_MODEL_LEN + 1);
178 	snprintf(wwn->model, sizeof(wwn->model),
179 		 "%." __stringify(INQUIRY_MODEL_LEN) "s", sdev->model);
180 	BUILD_BUG_ON(sizeof(wwn->revision) != INQUIRY_REVISION_LEN + 1);
181 	snprintf(wwn->revision, sizeof(wwn->revision),
182 		 "%." __stringify(INQUIRY_REVISION_LEN) "s", sdev->rev);
183 }
184 
185 static int
186 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
187 {
188 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
189 	int ret;
190 
191 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
192 	if (!buf)
193 		return -ENOMEM;
194 
195 	memset(cdb, 0, MAX_COMMAND_SIZE);
196 	cdb[0] = INQUIRY;
197 	cdb[1] = 0x01; /* Query VPD */
198 	cdb[2] = 0x80; /* Unit Serial Number */
199 	put_unaligned_be16(INQUIRY_VPD_SERIAL_LEN, &cdb[3]);
200 
201 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
202 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
203 	if (ret)
204 		goto out_free;
205 
206 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
207 
208 	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
209 
210 	kfree(buf);
211 	return 0;
212 
213 out_free:
214 	kfree(buf);
215 	return -EPERM;
216 }
217 
218 static void
219 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
220 		struct t10_wwn *wwn)
221 {
222 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
223 	int ident_len, page_len, off = 4, ret;
224 	struct t10_vpd *vpd;
225 
226 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
227 	if (!buf)
228 		return;
229 
230 	memset(cdb, 0, MAX_COMMAND_SIZE);
231 	cdb[0] = INQUIRY;
232 	cdb[1] = 0x01; /* Query VPD */
233 	cdb[2] = 0x83; /* Device Identifier */
234 	put_unaligned_be16(INQUIRY_VPD_DEVICE_IDENTIFIER_LEN, &cdb[3]);
235 
236 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
237 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
238 			      NULL, HZ, 1, NULL);
239 	if (ret)
240 		goto out;
241 
242 	page_len = get_unaligned_be16(&buf[2]);
243 	while (page_len > 0) {
244 		/* Grab a pointer to the Identification descriptor */
245 		page_83 = &buf[off];
246 		ident_len = page_83[3];
247 		if (!ident_len) {
248 			pr_err("page_83[3]: identifier"
249 					" length zero!\n");
250 			break;
251 		}
252 		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
253 
254 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
255 		if (!vpd) {
256 			pr_err("Unable to allocate memory for"
257 					" struct t10_vpd\n");
258 			goto out;
259 		}
260 		INIT_LIST_HEAD(&vpd->vpd_list);
261 
262 		transport_set_vpd_proto_id(vpd, page_83);
263 		transport_set_vpd_assoc(vpd, page_83);
264 
265 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
266 			off += (ident_len + 4);
267 			page_len -= (ident_len + 4);
268 			kfree(vpd);
269 			continue;
270 		}
271 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
272 			off += (ident_len + 4);
273 			page_len -= (ident_len + 4);
274 			kfree(vpd);
275 			continue;
276 		}
277 
278 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
279 		off += (ident_len + 4);
280 		page_len -= (ident_len + 4);
281 	}
282 
283 out:
284 	kfree(buf);
285 }
286 
287 static int pscsi_add_device_to_list(struct se_device *dev,
288 		struct scsi_device *sd)
289 {
290 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
291 	struct request_queue *q = sd->request_queue;
292 
293 	pdv->pdv_sd = sd;
294 
295 	if (!sd->queue_depth) {
296 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
297 
298 		pr_err("Set broken SCSI Device %d:%d:%llu"
299 			" queue_depth to %d\n", sd->channel, sd->id,
300 				sd->lun, sd->queue_depth);
301 	}
302 
303 	dev->dev_attrib.hw_block_size =
304 		min_not_zero((int)sd->sector_size, 512);
305 	dev->dev_attrib.hw_max_sectors =
306 		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
307 	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
308 
309 	/*
310 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
311 	 */
312 	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
313 
314 	/*
315 	 * Locate VPD WWN Information used for various purposes within
316 	 * the Storage Engine.
317 	 */
318 	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
319 		/*
320 		 * If VPD Unit Serial returned GOOD status, try
321 		 * VPD Device Identification page (0x83).
322 		 */
323 		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
324 	}
325 
326 	/*
327 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
328 	 */
329 	if (sd->type == TYPE_TAPE) {
330 		pscsi_tape_read_blocksize(dev, sd);
331 		dev->dev_attrib.hw_block_size = sd->sector_size;
332 	}
333 	return 0;
334 }
335 
336 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
337 		const char *name)
338 {
339 	struct pscsi_dev_virt *pdv;
340 
341 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
342 	if (!pdv) {
343 		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
344 		return NULL;
345 	}
346 
347 	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
348 	return &pdv->dev;
349 }
350 
351 /*
352  * Called with struct Scsi_Host->host_lock called.
353  */
354 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
355 	__releases(sh->host_lock)
356 {
357 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
358 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
359 	struct Scsi_Host *sh = sd->host;
360 	struct block_device *bd;
361 	int ret;
362 
363 	if (scsi_device_get(sd)) {
364 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
365 			sh->host_no, sd->channel, sd->id, sd->lun);
366 		spin_unlock_irq(sh->host_lock);
367 		return -EIO;
368 	}
369 	spin_unlock_irq(sh->host_lock);
370 	/*
371 	 * Claim exclusive struct block_device access to struct scsi_device
372 	 * for TYPE_DISK and TYPE_ZBC using supplied udev_path
373 	 */
374 	bd = blkdev_get_by_path(dev->udev_path,
375 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
376 	if (IS_ERR(bd)) {
377 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
378 		scsi_device_put(sd);
379 		return PTR_ERR(bd);
380 	}
381 	pdv->pdv_bd = bd;
382 
383 	ret = pscsi_add_device_to_list(dev, sd);
384 	if (ret) {
385 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
386 		scsi_device_put(sd);
387 		return ret;
388 	}
389 
390 	pr_debug("CORE_PSCSI[%d] - Added TYPE_%s for %d:%d:%d:%llu\n",
391 		phv->phv_host_id, sd->type == TYPE_DISK ? "DISK" : "ZBC",
392 		sh->host_no, sd->channel, sd->id, sd->lun);
393 	return 0;
394 }
395 
396 /*
397  * Called with struct Scsi_Host->host_lock called.
398  */
399 static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
400 	__releases(sh->host_lock)
401 {
402 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
403 	struct Scsi_Host *sh = sd->host;
404 	int ret;
405 
406 	if (scsi_device_get(sd)) {
407 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
408 			sh->host_no, sd->channel, sd->id, sd->lun);
409 		spin_unlock_irq(sh->host_lock);
410 		return -EIO;
411 	}
412 	spin_unlock_irq(sh->host_lock);
413 
414 	ret = pscsi_add_device_to_list(dev, sd);
415 	if (ret) {
416 		scsi_device_put(sd);
417 		return ret;
418 	}
419 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
420 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
421 		sd->channel, sd->id, sd->lun);
422 
423 	return 0;
424 }
425 
426 static int pscsi_configure_device(struct se_device *dev)
427 {
428 	struct se_hba *hba = dev->se_hba;
429 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
430 	struct scsi_device *sd;
431 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
432 	struct Scsi_Host *sh = phv->phv_lld_host;
433 	int legacy_mode_enable = 0;
434 	int ret;
435 
436 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
437 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
438 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
439 		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
440 			" scsi_lun_id= parameters\n");
441 		return -EINVAL;
442 	}
443 
444 	/*
445 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
446 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
447 	 */
448 	if (!sh) {
449 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
450 			pr_err("pSCSI: Unable to locate struct"
451 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
452 			return -ENODEV;
453 		}
454 		/*
455 		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
456 		 * reference, we enforce that udev_path has been set
457 		 */
458 		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
459 			pr_err("pSCSI: udev_path attribute has not"
460 				" been set before ENABLE=1\n");
461 			return -EINVAL;
462 		}
463 		/*
464 		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
465 		 * use the original TCM hba ID to reference Linux/SCSI Host No
466 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
467 		 */
468 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
469 			if (hba->dev_count) {
470 				pr_err("pSCSI: Unable to set hba_mode"
471 					" with active devices\n");
472 				return -EEXIST;
473 			}
474 
475 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
476 				return -ENODEV;
477 
478 			legacy_mode_enable = 1;
479 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
480 			sh = phv->phv_lld_host;
481 		} else {
482 			sh = scsi_host_lookup(pdv->pdv_host_id);
483 			if (!sh) {
484 				pr_err("pSCSI: Unable to locate"
485 					" pdv_host_id: %d\n", pdv->pdv_host_id);
486 				return -EINVAL;
487 			}
488 			pdv->pdv_lld_host = sh;
489 		}
490 	} else {
491 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
492 			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
493 				" struct Scsi_Host exists\n");
494 			return -EEXIST;
495 		}
496 	}
497 
498 	spin_lock_irq(sh->host_lock);
499 	list_for_each_entry(sd, &sh->__devices, siblings) {
500 		if ((pdv->pdv_channel_id != sd->channel) ||
501 		    (pdv->pdv_target_id != sd->id) ||
502 		    (pdv->pdv_lun_id != sd->lun))
503 			continue;
504 		/*
505 		 * Functions will release the held struct scsi_host->host_lock
506 		 * before calling calling pscsi_add_device_to_list() to register
507 		 * struct scsi_device with target_core_mod.
508 		 */
509 		switch (sd->type) {
510 		case TYPE_DISK:
511 		case TYPE_ZBC:
512 			ret = pscsi_create_type_disk(dev, sd);
513 			break;
514 		default:
515 			ret = pscsi_create_type_nondisk(dev, sd);
516 			break;
517 		}
518 
519 		if (ret) {
520 			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
521 				scsi_host_put(sh);
522 			else if (legacy_mode_enable) {
523 				pscsi_pmode_enable_hba(hba, 0);
524 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
525 			}
526 			pdv->pdv_sd = NULL;
527 			return ret;
528 		}
529 		return 0;
530 	}
531 	spin_unlock_irq(sh->host_lock);
532 
533 	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
534 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
535 
536 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
537 		scsi_host_put(sh);
538 	else if (legacy_mode_enable) {
539 		pscsi_pmode_enable_hba(hba, 0);
540 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
541 	}
542 
543 	return -ENODEV;
544 }
545 
546 static void pscsi_dev_call_rcu(struct rcu_head *p)
547 {
548 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
549 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
550 
551 	kfree(pdv);
552 }
553 
554 static void pscsi_free_device(struct se_device *dev)
555 {
556 	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
557 }
558 
559 static void pscsi_destroy_device(struct se_device *dev)
560 {
561 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
562 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
563 	struct scsi_device *sd = pdv->pdv_sd;
564 
565 	if (sd) {
566 		/*
567 		 * Release exclusive pSCSI internal struct block_device claim for
568 		 * struct scsi_device with TYPE_DISK or TYPE_ZBC
569 		 * from pscsi_create_type_disk()
570 		 */
571 		if ((sd->type == TYPE_DISK || sd->type == TYPE_ZBC) &&
572 		    pdv->pdv_bd) {
573 			blkdev_put(pdv->pdv_bd,
574 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
575 			pdv->pdv_bd = NULL;
576 		}
577 		/*
578 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
579 		 * to struct Scsi_Host now.
580 		 */
581 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
582 		    (phv->phv_lld_host != NULL))
583 			scsi_host_put(phv->phv_lld_host);
584 		else if (pdv->pdv_lld_host)
585 			scsi_host_put(pdv->pdv_lld_host);
586 
587 		scsi_device_put(sd);
588 
589 		pdv->pdv_sd = NULL;
590 	}
591 }
592 
593 static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
594 			       unsigned char *req_sense)
595 {
596 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
597 	struct scsi_device *sd = pdv->pdv_sd;
598 	struct pscsi_plugin_task *pt = cmd->priv;
599 	unsigned char *cdb;
600 	/*
601 	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
602 	 * not been allocated because TCM is handling the emulation directly.
603 	 */
604 	if (!pt)
605 		return;
606 
607 	cdb = &pt->pscsi_cdb[0];
608 	/*
609 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
610 	 * forced.
611 	 */
612 	if (!cmd->data_length)
613 		goto after_mode_sense;
614 
615 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
616 	    scsi_status == SAM_STAT_GOOD) {
617 		bool read_only = target_lun_is_rdonly(cmd);
618 
619 		if (read_only) {
620 			unsigned char *buf;
621 
622 			buf = transport_kmap_data_sg(cmd);
623 			if (!buf)
624 				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
625 
626 			if (cdb[0] == MODE_SENSE_10) {
627 				if (!(buf[3] & 0x80))
628 					buf[3] |= 0x80;
629 			} else {
630 				if (!(buf[2] & 0x80))
631 					buf[2] |= 0x80;
632 			}
633 
634 			transport_kunmap_data_sg(cmd);
635 		}
636 	}
637 after_mode_sense:
638 
639 	if (sd->type != TYPE_TAPE || !cmd->data_length)
640 		goto after_mode_select;
641 
642 	/*
643 	 * Hack to correctly obtain the initiator requested blocksize for
644 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
645 	 * struct scsi_device->sector_size will not contain the correct value
646 	 * by default, so we go ahead and set it so
647 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
648 	 * storage engine.
649 	 */
650 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
651 	     scsi_status == SAM_STAT_GOOD) {
652 		unsigned char *buf;
653 		u16 bdl;
654 		u32 blocksize;
655 
656 		buf = sg_virt(&cmd->t_data_sg[0]);
657 		if (!buf) {
658 			pr_err("Unable to get buf for scatterlist\n");
659 			goto after_mode_select;
660 		}
661 
662 		if (cdb[0] == MODE_SELECT)
663 			bdl = buf[3];
664 		else
665 			bdl = get_unaligned_be16(&buf[6]);
666 
667 		if (!bdl)
668 			goto after_mode_select;
669 
670 		if (cdb[0] == MODE_SELECT)
671 			blocksize = get_unaligned_be24(&buf[9]);
672 		else
673 			blocksize = get_unaligned_be24(&buf[13]);
674 
675 		sd->sector_size = blocksize;
676 	}
677 after_mode_select:
678 
679 	if (scsi_status == SAM_STAT_CHECK_CONDITION) {
680 		transport_copy_sense_to_cmd(cmd, req_sense);
681 
682 		/*
683 		 * check for TAPE device reads with
684 		 * FM/EOM/ILI set, so that we can get data
685 		 * back despite framework assumption that a
686 		 * check condition means there is no data
687 		 */
688 		if (sd->type == TYPE_TAPE &&
689 		    cmd->data_direction == DMA_FROM_DEVICE) {
690 			/*
691 			 * is sense data valid, fixed format,
692 			 * and have FM, EOM, or ILI set?
693 			 */
694 			if (req_sense[0] == 0xf0 &&	/* valid, fixed format */
695 			    req_sense[2] & 0xe0 &&	/* FM, EOM, or ILI */
696 			    (req_sense[2] & 0xf) == 0) { /* key==NO_SENSE */
697 				pr_debug("Tape FM/EOM/ILI status detected. Treat as normal read.\n");
698 				cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
699 			}
700 		}
701 	}
702 }
703 
704 enum {
705 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
706 	Opt_scsi_lun_id, Opt_err
707 };
708 
709 static match_table_t tokens = {
710 	{Opt_scsi_host_id, "scsi_host_id=%d"},
711 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
712 	{Opt_scsi_target_id, "scsi_target_id=%d"},
713 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
714 	{Opt_err, NULL}
715 };
716 
717 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
718 		const char *page, ssize_t count)
719 {
720 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
721 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
722 	char *orig, *ptr, *opts;
723 	substring_t args[MAX_OPT_ARGS];
724 	int ret = 0, arg, token;
725 
726 	opts = kstrdup(page, GFP_KERNEL);
727 	if (!opts)
728 		return -ENOMEM;
729 
730 	orig = opts;
731 
732 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
733 		if (!*ptr)
734 			continue;
735 
736 		token = match_token(ptr, tokens, args);
737 		switch (token) {
738 		case Opt_scsi_host_id:
739 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
740 				pr_err("PSCSI[%d]: Unable to accept"
741 					" scsi_host_id while phv_mode =="
742 					" PHV_LLD_SCSI_HOST_NO\n",
743 					phv->phv_host_id);
744 				ret = -EINVAL;
745 				goto out;
746 			}
747 			ret = match_int(args, &arg);
748 			if (ret)
749 				goto out;
750 			pdv->pdv_host_id = arg;
751 			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
752 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
753 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
754 			break;
755 		case Opt_scsi_channel_id:
756 			ret = match_int(args, &arg);
757 			if (ret)
758 				goto out;
759 			pdv->pdv_channel_id = arg;
760 			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
761 				" ID: %d\n",  phv->phv_host_id,
762 				pdv->pdv_channel_id);
763 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
764 			break;
765 		case Opt_scsi_target_id:
766 			ret = match_int(args, &arg);
767 			if (ret)
768 				goto out;
769 			pdv->pdv_target_id = arg;
770 			pr_debug("PSCSI[%d]: Referencing SCSI Target"
771 				" ID: %d\n", phv->phv_host_id,
772 				pdv->pdv_target_id);
773 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
774 			break;
775 		case Opt_scsi_lun_id:
776 			ret = match_int(args, &arg);
777 			if (ret)
778 				goto out;
779 			pdv->pdv_lun_id = arg;
780 			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
781 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
782 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
783 			break;
784 		default:
785 			break;
786 		}
787 	}
788 
789 out:
790 	kfree(orig);
791 	return (!ret) ? count : ret;
792 }
793 
794 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
795 {
796 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
797 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
798 	struct scsi_device *sd = pdv->pdv_sd;
799 	unsigned char host_id[16];
800 	ssize_t bl;
801 
802 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
803 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
804 	else
805 		snprintf(host_id, 16, "PHBA Mode");
806 
807 	bl = sprintf(b, "SCSI Device Bus Location:"
808 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
809 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
810 		host_id);
811 
812 	if (sd) {
813 		bl += sprintf(b + bl, "        Vendor: %."
814 			__stringify(INQUIRY_VENDOR_LEN) "s", sd->vendor);
815 		bl += sprintf(b + bl, " Model: %."
816 			__stringify(INQUIRY_MODEL_LEN) "s", sd->model);
817 		bl += sprintf(b + bl, " Rev: %."
818 			__stringify(INQUIRY_REVISION_LEN) "s\n", sd->rev);
819 	}
820 	return bl;
821 }
822 
823 static void pscsi_bi_endio(struct bio *bio)
824 {
825 	bio_put(bio);
826 }
827 
828 static inline struct bio *pscsi_get_bio(int nr_vecs)
829 {
830 	struct bio *bio;
831 	/*
832 	 * Use bio_malloc() following the comment in for bio -> struct request
833 	 * in block/blk-core.c:blk_make_request()
834 	 */
835 	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
836 	if (!bio) {
837 		pr_err("PSCSI: bio_kmalloc() failed\n");
838 		return NULL;
839 	}
840 	bio->bi_end_io = pscsi_bi_endio;
841 
842 	return bio;
843 }
844 
845 static sense_reason_t
846 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
847 		struct request *req)
848 {
849 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
850 	struct bio *bio = NULL;
851 	struct page *page;
852 	struct scatterlist *sg;
853 	u32 data_len = cmd->data_length, i, len, bytes, off;
854 	int nr_pages = (cmd->data_length + sgl[0].offset +
855 			PAGE_SIZE - 1) >> PAGE_SHIFT;
856 	int nr_vecs = 0, rc;
857 	int rw = (cmd->data_direction == DMA_TO_DEVICE);
858 
859 	BUG_ON(!cmd->data_length);
860 
861 	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
862 
863 	for_each_sg(sgl, sg, sgl_nents, i) {
864 		page = sg_page(sg);
865 		off = sg->offset;
866 		len = sg->length;
867 
868 		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
869 			page, len, off);
870 
871 		/*
872 		 * We only have one page of data in each sg element,
873 		 * we can not cross a page boundary.
874 		 */
875 		if (off + len > PAGE_SIZE)
876 			goto fail;
877 
878 		if (len > 0 && data_len > 0) {
879 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
880 			bytes = min(bytes, data_len);
881 
882 			if (!bio) {
883 new_bio:
884 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
885 				nr_pages -= nr_vecs;
886 				/*
887 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
888 				 */
889 				bio = pscsi_get_bio(nr_vecs);
890 				if (!bio)
891 					goto fail;
892 
893 				if (rw)
894 					bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
895 
896 				pr_debug("PSCSI: Allocated bio: %p,"
897 					" dir: %s nr_vecs: %d\n", bio,
898 					(rw) ? "rw" : "r", nr_vecs);
899 			}
900 
901 			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
902 				" bio: %p page: %p len: %d off: %d\n", i, bio,
903 				page, len, off);
904 
905 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
906 					bio, page, bytes, off);
907 			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
908 				bio_segments(bio), nr_vecs);
909 			if (rc != bytes) {
910 				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
911 					" %d i: %d bio: %p, allocating another"
912 					" bio\n", bio->bi_vcnt, i, bio);
913 
914 				rc = blk_rq_append_bio(req, &bio);
915 				if (rc) {
916 					pr_err("pSCSI: failed to append bio\n");
917 					goto fail;
918 				}
919 
920 				/*
921 				 * Clear the pointer so that another bio will
922 				 * be allocated with pscsi_get_bio() above.
923 				 */
924 				bio = NULL;
925 				goto new_bio;
926 			}
927 
928 			data_len -= bytes;
929 		}
930 	}
931 
932 	if (bio) {
933 		rc = blk_rq_append_bio(req, &bio);
934 		if (rc) {
935 			pr_err("pSCSI: failed to append bio\n");
936 			goto fail;
937 		}
938 	}
939 
940 	return 0;
941 fail:
942 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
943 }
944 
945 static sense_reason_t
946 pscsi_parse_cdb(struct se_cmd *cmd)
947 {
948 	if (cmd->se_cmd_flags & SCF_BIDI)
949 		return TCM_UNSUPPORTED_SCSI_OPCODE;
950 
951 	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
952 }
953 
954 static sense_reason_t
955 pscsi_execute_cmd(struct se_cmd *cmd)
956 {
957 	struct scatterlist *sgl = cmd->t_data_sg;
958 	u32 sgl_nents = cmd->t_data_nents;
959 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
960 	struct pscsi_plugin_task *pt;
961 	struct request *req;
962 	sense_reason_t ret;
963 
964 	/*
965 	 * Dynamically alloc cdb space, since it may be larger than
966 	 * TCM_MAX_COMMAND_SIZE
967 	 */
968 	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
969 	if (!pt) {
970 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
971 	}
972 	cmd->priv = pt;
973 
974 	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
975 		scsi_command_size(cmd->t_task_cdb));
976 
977 	req = blk_get_request(pdv->pdv_sd->request_queue,
978 			cmd->data_direction == DMA_TO_DEVICE ?
979 			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
980 	if (IS_ERR(req)) {
981 		pr_err("PSCSI: blk_get_request() failed\n");
982 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
983 		goto fail;
984 	}
985 
986 	if (sgl) {
987 		ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
988 		if (ret)
989 			goto fail_put_request;
990 	}
991 
992 	req->end_io = pscsi_req_done;
993 	req->end_io_data = cmd;
994 	scsi_req(req)->cmd_len = scsi_command_size(pt->pscsi_cdb);
995 	scsi_req(req)->cmd = &pt->pscsi_cdb[0];
996 	if (pdv->pdv_sd->type == TYPE_DISK ||
997 	    pdv->pdv_sd->type == TYPE_ZBC)
998 		req->timeout = PS_TIMEOUT_DISK;
999 	else
1000 		req->timeout = PS_TIMEOUT_OTHER;
1001 	scsi_req(req)->retries = PS_RETRY;
1002 
1003 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1004 			(cmd->sam_task_attr == TCM_HEAD_TAG),
1005 			pscsi_req_done);
1006 
1007 	return 0;
1008 
1009 fail_put_request:
1010 	blk_put_request(req);
1011 fail:
1012 	kfree(pt);
1013 	return ret;
1014 }
1015 
1016 /*	pscsi_get_device_type():
1017  *
1018  *
1019  */
1020 static u32 pscsi_get_device_type(struct se_device *dev)
1021 {
1022 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1023 	struct scsi_device *sd = pdv->pdv_sd;
1024 
1025 	return (sd) ? sd->type : TYPE_NO_LUN;
1026 }
1027 
1028 static sector_t pscsi_get_blocks(struct se_device *dev)
1029 {
1030 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1031 
1032 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1033 		return pdv->pdv_bd->bd_part->nr_sects;
1034 
1035 	return 0;
1036 }
1037 
1038 static void pscsi_req_done(struct request *req, blk_status_t status)
1039 {
1040 	struct se_cmd *cmd = req->end_io_data;
1041 	struct pscsi_plugin_task *pt = cmd->priv;
1042 	int result = scsi_req(req)->result;
1043 	u8 scsi_status = status_byte(result) << 1;
1044 
1045 	if (scsi_status) {
1046 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1047 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1048 			result);
1049 	}
1050 
1051 	pscsi_complete_cmd(cmd, scsi_status, scsi_req(req)->sense);
1052 
1053 	switch (host_byte(result)) {
1054 	case DID_OK:
1055 		target_complete_cmd_with_length(cmd, scsi_status,
1056 			cmd->data_length - scsi_req(req)->resid_len);
1057 		break;
1058 	default:
1059 		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1060 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1061 			result);
1062 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1063 		break;
1064 	}
1065 
1066 	blk_put_request(req);
1067 	kfree(pt);
1068 }
1069 
1070 static const struct target_backend_ops pscsi_ops = {
1071 	.name			= "pscsi",
1072 	.owner			= THIS_MODULE,
1073 	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH |
1074 				  TRANSPORT_FLAG_PASSTHROUGH_ALUA |
1075 				  TRANSPORT_FLAG_PASSTHROUGH_PGR,
1076 	.attach_hba		= pscsi_attach_hba,
1077 	.detach_hba		= pscsi_detach_hba,
1078 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1079 	.alloc_device		= pscsi_alloc_device,
1080 	.configure_device	= pscsi_configure_device,
1081 	.destroy_device		= pscsi_destroy_device,
1082 	.free_device		= pscsi_free_device,
1083 	.parse_cdb		= pscsi_parse_cdb,
1084 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1085 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1086 	.get_device_type	= pscsi_get_device_type,
1087 	.get_blocks		= pscsi_get_blocks,
1088 	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
1089 };
1090 
1091 static int __init pscsi_module_init(void)
1092 {
1093 	return transport_backend_register(&pscsi_ops);
1094 }
1095 
1096 static void __exit pscsi_module_exit(void)
1097 {
1098 	target_backend_unregister(&pscsi_ops);
1099 }
1100 
1101 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1102 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1103 MODULE_LICENSE("GPL");
1104 
1105 module_init(pscsi_module_init);
1106 module_exit(pscsi_module_exit);
1107